Rodinal Substitutes?

[Gerald Koch]

Gerald, please note the fact that bromide was added to Rodinol when they stopped using the hydrochloride salt of the pAp.

This event is not insignificant IMHO.

PE

I think that may be a coincidence since chloride ion is such a feeble restrainer.

 

[gainer]

Patrick, the interaction between sulfite and chloride is not a simple matter to just state as a fact. The antifoggant action betweeen chloride and an emulsion are in the same category. It is impossible to give the entire relationship in a complete manner when also considering the interactions possible. I merely bring them up.

I don't intend to disclose that information until I can confirm the relationships myself, but the matter is quite complex as Kirk has elucidated. It is clear that you have not considered the entire gamut of Rodinol solutions yourself Patrick.

PE

it is clear that nothing about me is clear to you.

 

[gainer]

Sorry about that. I couldn't help it. I just think these forums are for people who need to know to ask questions for people who know to answer. When I state an opinion based on what I have seen, it doesn't bother me when someone else sees it differently. It bothers me when someone implies that I am stupid for seeing it my way.

My entire problem with making a Rodinal clone by the traditional method is the idea of a sort of titration operation that is slow in reacting and where overshoot is worse than undershoot. Whether you start with the hydrochloride or the base, when the cleverness is in leaving some of the base precipitated as a protection against aerial oxidation, it seems to me that leaving too much may be wasteful but not photographically harmful. Any way you go about it, if you put in the calculated amounts of ingredients you will either have some precipitate or not. If not, you can add some p-aminophenol. If so, you can leave well enough alone. he niceties, such as chloride or bromide or sulfite content, you can add to suit your taste just as with any other developer. With Rodinal, we tend to worry about whether we made it the right way, but if it works, we keep using it until it's as old as Methusaleh and black as tar and brag about the 20 year old Rodinal that still works.

 

[Gerald Koch]

I have never had any problem with making any of the Rodinal formulas. But then I use a magnetic stirrer which makes things easier.

 

[Earl Dunbar]

I have never had any problem with making any of the Rodinal formulas. But then I use a magnetic stirrer which makes things easier.

They're fun to watch, too.

Earl

 

[dancqu]

The rather odd preparation of the developer
makes perfect sense when one considers chemical
manufacture a century ago.

I think that point well taken. I've for some time pondered
the reason for the persulfate step in the preparation of
Nelson's Gold Toner. I think now that at some distant
time past sodium thiosulfate must not have been
clear of sulfite. For what other reason?

Then there is developer composition due to way of
usage. How many, many, many formulas contain
100 grams of sodium sulfite. Dan

 

[gainer]

I think that may be a coincidence since chloride ion is such a feeble restrainer.

Well, if there is a significant difference between making it with the base or the hydrochloride, I cannot see it in my results, either in the base fog or the contrast index. I measure log illumination at the baseboard to the nearest 0.01 base 10 log units. I added no bromide or other restrainer in either case.

Some years ago I found that there are two ways to improve Rodinal, and neither involved adding of sulfite , chloride or bromide. Rodinal with added sodium ascorbate showed its usual sharpness with better actual resolution. Rodinal with a small amount of borax reduced base fog.

 

[gainer]

I think that point well taken. I've for some time pondered
the reason for the persulfate step in the preparation of
Nelson's Gold Toner. I think now that at some distant
time past sodium thiosulfate must not have been
clear of sulfite. For what other reason?

Then there is developer composition due to way of
usage. How many, many, many formulas contain
100 grams of sodium sulfite. Dan

You may have noticed that in a lot of tests to find optimum composition, sulfite content is taken for granted. No one can tell what the optimum D-76 is when you hold the developing agents and borax (or borate buffer) constant. What would happen if you didn't have any? The MQ combination needs some, or you get a staining developer akin, but not equal to, Pyrocat HD. But how much is the least you can get away with? Well, everybody knows the grain would be tremendous and the film speed would go down. Or do they?

 

[Gerald Koch]

Some years ago I found that there are two ways to improve Rodinal, and neither involved adding of sulfite , chloride or bromide. Rodinal with added sodium ascorbate showed its usual sharpness with better actual resolution. Rodinal with a small amount of borax reduced base fog.

In the first case you are adding an additional developing agent to the Rodinal. According to the two formulators of Xtol, ascorbate based developers produce ~10% finer grain than other developers.

It has been known for some time that borates can suppress developer fog.

 

[pauldc]

Some years ago I found that there are two ways to improve Rodinal, and neither involved adding of sulfite , chloride or bromide. Rodinal with added sodium ascorbate showed its usual sharpness with better actual resolution. Rodinal with a small amount of borax reduced base fog.

Can I check I am clear on this (I have read the Unblinkingeye material and have been wondering about this for a while so forgive my confusion) - is it advisable to add both sodium ascorbate AND borax to the same solution or do you have to choose one or the other? i.e. is there the win/win of improving resolution through the ascorbate and reducing base fog at the same time.

Many thanks.

 

[Kirk Keyes]

It has been known for some time that borates can suppress developer fog.

And doesn't the borax lower the pH which would decrease the activity of the developer?

 

[Lee L]

Based on Gainer's information here, on unblinkingeye, and elsewhere, I tried this yesterday on a first roll of Efke 50.

I mixed Rodinal 1+100 using a 1% Borax (20 Mule Team) stock solution, and added sodium ascorbate at the rate of 1 gram per 5 ml of Rodinal used (3cc Rodinal in this case requiring 0.6g sodium ascorbate). Gainer mentions somewhere a general rule of thumb that adding sodium ascorbate at this rate means you should use a time for half that dilution rate to compensate for increased activity. E.g. if you add sodium ascorbate to a 1+50 dilution, use the recommended development time for a 1+25 dilution. I took a recommended time for 1+50 to use with my 1+100.

I understand that the borax should decrease activity, but I also use a low rate of agitiation and extended times to keep contrast down and build shadows. The recommended 1+50 time was 9 minutes, so I extended to 12 minutes (based on my experience with using other films at 12 minutes with "normal" agitation and extending to 18 minutes with less agitation) and used continuous agitation for the first minute, then two inversions in five seconds once each three minutes for the remaining time. BTW, this was my son doing the actual developing as well. E.I. was set for 50.

I got what look like very good results, but have some caveats. This was my older son's first roll of B&W, and the exposures were his choices, so I can't speak authoritatively to the full speed rating. However, he shoots a lot of Velvia and does well there, and the negs looked properly exposed. This is also the first roll of Efke 50 I've done, so I have no benchmark for judging relative graininess. Contrast looks good, but I didn't do control density frames, so can't give you a gamma, and I haven't printed anthing from this roll using a straight graded filter, so no standard there to go by yet either. Given all that, I'd start at the same place for a real test roll.

Lee

 

[avandesande]

Rodinal isn't very grainy at 1:100. You may want to try it without the other stuff.

 

[gainer]

And doesn't the borax lower the pH which would decrease the activity of the developer?

It does lower activity somewhat. Ascorbate increases it somewhat, as it is superadditive with p-aminophenol.

I think the appearance of potassium hydroxide on the Rodinal label makes us believe the pH is higher than it really is in the working solution. I don't have a pH meter to test it, but from my experiences with various schemes for homebrewing it I find that practically all the hydroxide goes into neutralizing the hydrochloric acid on the tail end of the p-aminophenol.HCl, and the potassium metabisulfite that is usually used. The appearance of a precipitate of p-aminophenol is a sign that all the availale sodium or potassium hydroxide has been used to make sodium aminophenolate. The sodium aminophenolate is probably at least 12, as has been pointed out, but a 1+50 dilution of Rodinal will not develop when I add 4 g/l of ascorbic acid. It must therefore not have a high buffer capacity. I must use the ascorbate or add more alkali to make it in the working solution.

 

[Gerald Koch]

The Agfa MSDS for Rodinal says that the pH of the concentrate is ~14 and that of the working solution is 11.55.

 

[nworth]

Patrick, it is not as simple as you portray.

...

I said to you once before, I would never try to design an airplane. Kirk and I are chemists. He is on the right track and most everyone is missing three essential factoids about this developer. Maybe more. I'm still studying the chemistry. It is fascinating (as Mr. Spock would say.).

PE

Having been trained as a chemist but having spent most of my active professional life as a systems engineer (a lot of it on missiles), I think I understand where both you and Gainer are coming from, and I appreciate both sets of opinions. Empirical results are very valuable, but it's nice to know why things happened that way. Kirk has described, very well, some of the chemistry involved in the usual preparation of Rodinal. This parallels what Mees wrote some 50 years ago. Of course, we are talking about solution chemistry in water, and, on the micro level, that gets extremely complicated. (I doubt that it is really fully understood). What the final products are, depending on the order of solution, would probably best be left to measurement.

One thing I have noticed is that much of he p-aminophenol.HCl available these days is very impure - contaminated with polymers and pot tar. The good stuff is pure white, and the reactions Kirk cited change the solution to tan or brown. I'm not sure what the gunk does to the developer, but people still seem to make successful Rodinal-type soup from it.

 

[dancqu]

It does lower activity somewhat. Ascorbate increases
it somewhat, as it is superadditive with p-aminophenol.

Would it not have done just to lower the ph? Would
the development times have become to long? So the
ascorbate to keep short development times; it being
so little an amount as to not affect to
any degree the ph. Dan

 

[fhovie]

Ahhhh - the bliss of being an intuitive instead of an analytical:

VERY
COMPLICATED ----> A MIRACLE OCCURS -----> WONDERFUL RESULT
PROCESS

I am fine with this - just tell me the recipe and I will mix it. I have yet to try Rodinal - probably never will. There are too many developers that have Rodinal benefits without the Rodinal drawbacks. --- Probably more like PMK than anything else.

 

[gainer]

Would it not have done just to lower the ph? Would
the development times have become to long? So the
ascorbate to keep short development times; it being
so little an amount as to not affect to
any degree the ph. Dan

The addition of ascorbate to Rodinal came out of an article I wrote for Photo Techniques called "Salt to Taste" in which I started out to test the effects of adding sodium chloride to D-23 and Rodinal. Somewhere along the line I found that neither great gobs of salt nor great gobs of sulfite helped Rodinal. They changed it, but not in any way I would like. Adding ascorbate seemed to improve its grain without decreasing its sharpness.

It did produce somewhat more fog than plain Rodinal. The purpose of adding borax was in fact to lower pH. If that is all that is needed, it is better than adding bromide when it comes to shadow detail.

 

[Tom Hoskinson]

Another Acutance developer (Glycin based) that gives Rodinal "a good run for its money" is Agfa 8. Agfa 8 is a mix-it-yourself developer. I posted the Recipe in an APUG thread a few months ago. An APUG search on Agfa 8 should find it.

 

[gainer]

The Agfa MSDS for Rodinal says that the pH of the concentrate is ~14 and that of the working solution is 11.55.

Gerald, I probably should look it up myself, but is the working pH you posted for 1+25?

It would take about 1 gram of NaOH or equivalent to make sodium ascorbate out of 4 grams of ascorbic acid. That's about 0.025 moles each of NaOH and ascorbic acid. In a liter, I'm guessing pH of about 12 to start and about 7.6 after adding the ascorbic acid. One can see why adding the acid to diluted Rodinal would kill it.

I sometimes wish I had continued my study of chemical engineering, but I would have missed a lot of fun at NACA-NASA if I had.

 

[Gerald Koch]

I'm guessing but since 1+25 appears to be Agfa recommended dilution I would suspect the quoted pH is for this dilution.

 

[gainer]

By the way, my only experience with designing an airplane was in my senior year at WVU. My work at NACA-NASA was analysis of flight test data, analysis of some wind tunnel data, design of star charts, "non-linear mathematical models of the human operator", design of planetarium projector, design of apparatus for observing and measuring pilots' eye movements and correlating them with piloting tasks, and some photography. I forget all the other things.

 

[gainer]

Oh yes. The part of the airplane we had to design and analyze structurally was the main wing spar. The instructor was expecting a design involving channel at top and bottom with sheet webbing and myriads of rivrts. I made mine in one piece of sheet metal after consulting to find if fabrication was feasible. He was a little taken aback because it didn't require me to exhibit my lack of ability to design riveted structures, but my design weighed about the same and was several times stronger. He had to give me credit because all he asked for was a wing spar for a certain wing shape.

If you are very specific about what you want someone to design and how, you may not get the best that person can do. Ask for the what and leave out the how.

 

[Jürgen]

Pat,I have mixed up a 250mL batch of you formula, and gave it a test spin on some tmax 400, at 1:50 for 10 minutes. The negatives look about the right for the lighting conditions. It may not be an exact copy of rodinal but it works in a similar fashion.

Jurgen